Department of Psychology, College of Liberal Arts and Sciences, Arizona State University, and Arts, Media and Engineering Program, Herberger College of Fine Arts and Ira A. Fulton School of Engineering, Arizona State University

Christopher Todd

Arts, Media and Engineering Program, Herberger College of Fine Arts and Ira A. Fulton School of Engineering, Arizona State University

David Birchfield

Arts, Media and Engineering Program, Herberger College of Fine Arts and Ira A. Fulton School of Engineering, Arizona State University, and School of Music, Herberger College of Fine Arts, Arizona State University

Michael McBeath

Department of Psychology, College of Liberal Arts and Sciences, Arizona State University

Harvey Thornburg

Arts, Media and Engineering Program, Herberger College of Fine Arts and Ira A. Fulton School of Engineering, Arizona State University, and Department of Electrical Engineering, Ira A. Fulton School of Engineering, Arizona State University

Work by Morikawa (1999) and Dolgov, et al. (2005) confirmed that stationary observers reliably misjudge projected destination of axis-misaligned figures in the direction the axis is tilted, a phenomenon we named “Axis-Aligned Motion” (AAM) bias. The current study evaluates whether or not the AAM bias is diminished if observers can respond with a navigational action versus stationary pointing. Participants observed moving symmetric and asymmetric figures in a large, overhead-projection, situated-display environment. The task was to judge projected destination of figures that move along the floor and then disappear midway across a colored 3 meter diameter circle. Eight participants completed 24 trials in each of the 3 experimental conditions: 1) stationary observers estimating projected destination of shapes using a laser pointer; 2) mobile observers that begin walking to the projected destination after the shape finishes moving; and 3) mobile observers that begin walking as soon as the shape begins to move. Replicating previous research, stationary observers reliably misjudge projected destination of axis-misaligned moving figures in the direction the axis tilts. Across all conditions, final destinations of axis-aligned symmetric shapes were judged significantly more accurately than asymmetric and axis-misaligned symmetric shapes (p[[lt]]0.05). The impact of locomotive action on the AAM bias was supported by the absolute magnitude of error being significantly greater (p[[lt]]0.05) in the stationary versus mobile conditions, which did not significantly differ from one another. The findings confirm the existence of the AAM bias in a large situated-display environment and demonstrate that its influence on motion perception can be mitigated by allowing observers to locomote to the estimated destination. They support that AAM is a natural regularity for which observers have developed a bias, and that this bias is diminished for navigational action tasks such interception, consistent with previous research demonstrating differences in perceptual phenomena for stationary versus active tasks.